CDA6530:%20Performance%20Models%20of%20Computers%20and%20Networks%20Project%203%20Q

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CDA6530 Performance Models of Computers and
NetworksProject 3 QA
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• m 300 n 300
• Structure definition in Matlab
• Nodestruct('status', zeros(m,n), 'infectTime',
  zeros(m,n), 'InfectOtherTime', zeros(m,n))
• Or you can define
• NodeState zeros(m,n)
• NodeInfectTime zeros(m,n)
• NodeInfectOtherTime zeros(m,n)

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Multiple Way to Remember Infection Traffic

• Define a queue variable to remember
• Generated infection traffic source (or
  destination)
• Active time (when the source passes the traffic
  to all its neighbors, or when a vulnerble node
  receives the traffic)
• Quite complicated since the event queue is very
  dynamic

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Multiple Way to Remember Infection Traffic (my
approach)

• Use each infected node variable to remember when
  its outgoing infection traffic reach its
  neighbors
• NodeInfectOtherTime(i,j) save the time for
  infection traffic reaching the node(i,j)s
  neighbors

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• How to determine neighboring nodes?
• You dont need the code to remember the topology
  since it is so regular
• Node(a,b)s 4 neighbors
• Upper node (a-1,b), Down node (a1, b)
• Left node (a,b-1), right node (a, b1)
• Make sure you check if any of the above 4 nodes
  are non-exist
• For S2, you also need to check if the node is one
  of those 10 shortcut nodes
• If yes, considering the 5th neighboring node

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• How to decide the simulation end time?
• At current discrete time k, check all nodes
• If all (NodeInfectOtherTime(.,.) lt k), then stop
• It means there does not exist any future
  infection traffic anymore

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Infection Activity from sending node angle

• At current time t
• If the NodeState(j,k) infected
• If the NodeInfectOtherTime(j,k) t,
• the node infection traffic reach its neighbors
  now!
• Check all its neighbors to see if any neighbor is
  infected now, if the neighbor node(a, b) is
  infected now
• NodeState(a,b) infected
• NodeInfectTime(a,b) t
• generate Poisson distr. delay time x
• NodeInfectOtherTime(a,b) x t 1
• If NodeState(j,k) vulnerable
• Do nothing

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Two Actions for Every Infected Node

• Act 1 when node(a,b) becomes infected at current
  discrete time t
• Change its status NodeState(a,b) INFECTED
• Assign
• NodeInfectTime(a,b) t
• x PoissonGenerator()
• NodeInfectOtherTime(a,b) t x 1
• Act 2 when an infected node delivers infection
  traffic to its neighbors
• When? if (NodeState(a,b) INFECTED
• t
  NodeInfectOtherTime(a,b) )
• Check each of its neighbor
• If neighbor node(c,d) is vulnerable and will be
  infected?
• Run Act 1 for the node(c,d)

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• startTime cputime
• Simulation.
• simulateCPUTime cputime startTime